US5369277A - Infrared source - Google Patents
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- US5369277A US5369277A US07/598,984 US59898490A US5369277A US 5369277 A US5369277 A US 5369277A US 59898490 A US59898490 A US 59898490A US 5369277 A US5369277 A US 5369277A
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Classifications
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N21/05—Flow-through cuvettes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N21/0303—Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/10—Arrangements of light sources specially adapted for spectrometry or colorimetry
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/30—Measuring the intensity of spectral lines directly on the spectrum itself
- G01J3/36—Investigating two or more bands of a spectrum by separate detectors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
- G01N21/03—Cuvette constructions
- G01N2021/0346—Capillary cells; Microcells
Definitions
- the present invention relates to novel, improved devices for emitting energy in the infrared part of the electromagnetic spectrum.
- the gas analyzers disclosed in the '858 and '859 patents are of the non-dispersive type. They operate on the premise that the concentration of a designated gas can be measured by: (1) passing a beam of infrared radiation through the gas, and (2) then ascertaining the attenuated level of the energy in a narrow band absorbable by the designated gas. This is done with a detector capable of generating a concentration proportional electrical output signal.
- capnometers for monitoring the level of carbon dioxide in the breath of a medical patient. This is typically done during a surgical procedure as an indication to the anesthesiologist of the patient! s condition. As the patient's well being, and even his life, is at stake, it is of paramount importance that the carbon dioxide concentration be measured with great accuracy.
- the infrared radiation is emitted from a source and focused by a mirror on the gases being analyzed. After passing through the body of gases, the beam of infrared radiation passes through a filter. That filter absorbs all of the radiation except for that in a narrow band centered on a frequency which is absorbed by the gas of concern. This narrow band of radiation is transmitted to a detector which is capable of producing an electrical output signal proportional in magnitude to the magnitude of the infrared radiation impinging upon it.
- the radiation in the band passed by the filter is attenuated to an extent which is proportional to the concentration of the designated gas.
- the strength of the signal generated by the detector is consequently inversely proportional to the concentration of the designated gas and can be inverted to provide a signal indicative of that concentration.
- the source or emitter which produces the beam of infrared radiation.
- the emitter has a substrate of a material with low thermal conductivity such as steatite.
- Two T-shaped conductors or terminals are bonded to the upper surface of the substrate in spaced relationship; and a film of an emissive, electrically resistive material is superimposed on the conductors and bonded to the upper surface of the substrate with its ends overlapping and electrically connected to the conductors.
- This emitter is attached to posts at its opposite ends and supported by those posts from a metallic emitter mount with the emissive film facing the mount. That component has a polished, parabolic, mirror surface formed in the surface which the emitter faces. This mirror collimates the emitted infrared radiation and focuses the collimated radiation into a beam directed along the optical path of the device or system in which the infrared radiation source is employed.
- the substrate bearing the emissive film was fixed at both of its ends to the supporting posts. As the substrate was heated by the emissive film, it grew or increased in length due to thermal expansion. This has led to failure of the patented type of infrared radiation source because of the stresses that were consequently imposed on the substrate and substrate-supported components.
- the novel infrared radiation sources of the present invention are like those disclosed in the '858 and '859 patents in that they have a low thermal conductivity substrate supporting a film-type emissive element.
- they differ in one important respect in that the ends of the substrate are not fixed at an invariable distance relative to each other. Instead, one end is fixed to a lead frame, which serves as a support for the substrate-based emitter component; and the opposite end of the substrate is left free to move relative to the lead frame. Consequently, the substrate is free to grow in length as its temperature increases; and the imposition of mechanical stresses on the emitter unit is thereby avoided.
- the lead frame-based approach also facilitates assembly. For example, electrical connections are easier to make (and also less apt to break); and the heretofore need for insulated leads is eliminated. Also, the film-type emissive element is automatically centered on the axis of the energy collimating and focusing mirror. This simplifies, and reduces the cost of, the assembly process by eliminating the steps heretofore employed to insure that the emissive element was accurately aligned with the collimating mirror.
- the components of the herein disclosed infrared radiation sources are primarily molded from plastics rather than being machined from metal as in the patented sources. This allows an acceptable degree of accuracy to be maintained while significantly reducing the cost of the parts.
- the novel design of the herein disclosed infrared radiation sources allows the collimating mirror to be assembled last. This minimizes the possibility that the mirrored surface might be scratched or otherwise damaged. That is important because the mirror is the most expensive part of the infrared radiation source.
- infrared radiation sources disclosed herein are so balanced and correlated that the flow of heat away from the operating emissive element is closely controlled and correlated with the emitted infrared energy. This results in an infrared radiation source which can be made to emit infrared radiation of accurately predictable intensity. This is important.
- Infrared radiation sources as disclosed in the foregoing patents, as well as those disclosed herein, can also be used for a variety of other purposes.
- Infrared sources .of the type to which the present invention relates commonly employ a heated, electrically resistive film on an appropriate substrate as an emitter of infrared radiation.
- This unit has heretofore been fixed at its opposite ends to a suitable support so that the necessary electrical connections to the emissive layer can conveniently be made. As discussed above, such infrared radiation sources frequently fail.
- Still another important and primary object of the invention resides in the provision of novel methods for assembling an infrared radiation source or emitter unit of the character identified in the preceding objects.
- FIG. 1 is an exploded view of: (a) an airway adapter which provides a particularized flow path for a gas being analyzed, and (b) a transducer which outputs a signal indicative of the concentration of the designated gas in the mixture and a reference signal; that transducer includes an infrared radiation source or emitter unit constructed in accord with the principles of the present invention;
- FIG. 2 is a section through, and depicts, a detector-incorporating optical system of the airway adapter/transducer assembly
- FIG. 3 is an exploded view of the infrared radiation source
- FIG. 4 is a second exploded view presented to show the relationship between: (a) a lead frame employed in the device to support the infrared radiation emitting element and to make electrical connections to that unit, and (b) a molded ring which supports the lead frame and is the base of the device;
- FIG. 5 is a plan view, prior to its being installed in the base, of an assembly made up of the infrared radiation emitter unit and the supporting lead frame;
- FIG. 6 is a fragmentary, pictorial view of the emitter unit/lead frame assembly; this figure shows a novel floating relationship between the emitter unit and the lead frame which allows the emitter to freely grow in length as the emitter unit temperature increases, thereby eliminating the imposition of stresses which might damage the emitter unit or electrical connections to that unit;
- FIG. 7 is a vertical section through a parabolic mirror component employed in the infrared radiation source to collimate, focus into a beam, and direct along a specific optical path infrared radiation outputted by the emitter unit;
- FIG. 8 is a plan view of the assembled source or device
- FIGS. 9 and 10 are sections through the device taken essentially along lines 9--9 and 10--10 of FIG. 8;
- FIG. 11 is a block diagram of an electronic driver for the infrared radiation emitter unit
- FIG. 12 is an elevation of a second infrared radiation source also embodying the principles of the present invention.
- FIG. 13 is a second elevation of the source shown in FIG. 12, in this case looking in the direction indicated by arrows 13--13 in FIG. 12;
- FIG. 14 is a section through the infrared radiation source shown in FIG. 12 taken substantially along lines 14--14 of FIG. 13;
- FIG. 15 is a section through the source of FIG. 12, taken substantially along line 15--15 of FIG. 16;
- FIG. 16 is a section through the source, taken substantially along line 16--16 of FIG. 12;
- FIG. 17 is a fragmentary plan view of a lead frame component employed in the device of FIG. 12;
- FIG. 18 is a vertical section through a parabolic mirror component employed in the infrared radiation source to collimate, focus into a beam, and direct along a specific optical path infrared radiation outputted by the emitter unit;
- FIG. 19 is a block diagram of detector and case heater systems employed in the transducer shown in FIG. 1.
- the principles of the present invention can be employed to particular advantage in transducers for outputting: (a) a signal proportional in magnitude to the concentration of carbon dioxide flowing through an airway adapter in a patient-to-mechanical ventilator circuit, and (b) a reference signal. These signals can be ratioed in the manner disclosed in above-incorporated U.S. Pat. Nos. 4,859,858, and 4,859,859 to provide a third signal accurately and dynamically representing the concentration of the carbon dioxide flowing through the airway adapter.
- a representative and preferred airway adapter and a complementary transducer constructed in accord with, and embodying, the principles of the present invention are shown in FIGS. 1 and 2 and respectively identified by reference characters 22 and 24.
- FIG. 1 shows primarily the polymeric housing 26 of transducer 24.
- This transducer also includes: (a) an infrared radiation emitter unit 28 (FIGS. 1-10); (b) a detector unit 30 (FIG. 2); and (c) a detector unit power supply 32.
- the illustrated airway adapter 22 is designed for connection between an endotracheal tube inserted in a patient's trachea and the plumbing of a mechanical ventilator, and transducer 24 is in this instance employed to measure the expired carbon dioxide level of a medical patient.
- airway adapter 22 is a one-piece unit typically molded from Valox polyester or a comparable polymer.
- Airway adapter 22 has a generally parallelepipedal center section 34 and two cylindrical end sections 36 and 38 with a sampling passage 40 extending from end-to-end through the adapter. End sections 36 and 38 are axially aligned with center section 34.
- the central section 34 of airway adapter 22 provides a seat for transducer 24.
- An integral, U-shaped casing element 42 positively locates transducer 24 endwise of the adapter and, also, in that transverse direction indicated by arrow 44 in FIG. 1. That arrow also shows the direction in which airway adapter 22 is displaced to assemble it to transducer 24.
- Apertures 46 and 48 are formed in the center section 34 of airway adapter 22. With transducer 24 assembled to the airway adapter, these apertures are aligned along an optical path identified by reference character 50 in FIG. 2. That optical path extends from the infrared radiation emitter unit 28 in transducer 24 transversely across airway adapter 22 and the gas(es) flowing therethrough to the infrared radiation detector unit 30 of transducer 24.
- the apertures are sealed by sapphire windows 52 and 54.
- Sapphire windows are employed because other materials such as glass or plastic would absorb the infrared radiation to an extent that would significantly degrade the quality of the signals generated in detector unit 30.
- That casing 26 of transducer 24 in which the source unit 28 and detector unit 30 are housed has first and second end sections 58 and 60 with a rectangularly configured gap 62 therebetween. With the transducer assembled to airway adapter 22, the two sections 58 and 60 of transducer casing 26 embrace those two inner side walls 64 and 66 of airway adapter central section 34 in which energy transmitting windows 52 and 54 are installed.
- Optically transparent windows 68 and 70 are installed along optical path 50 in apertures 72 and 74 provided in the inner end walls 76 and 78 of transducer housing 26. These windows allow the beam of infrared radiation generated in unit 28 in the left-hand end section 58 of transducer housing 26 to pass airway adapter 22 and from the airway adapter to the detector unit 30 in the right-hand section 60 of the transducer housing. At the same time, windows 68 and 70 keep foreign material from penetrating to the interior of the transducer casing.
- the unit 28 employed to emit infrared radiation, to form that energy into a beam, and to propagate the beam along optical path 50 includes: an infrared radiation emitter 80, a lead frame 82, a tube or cap 84, and a mirror component 86, all supported from a base 88.
- Infrared emitter or energy source 80 is of a unique thick film construction. It includes a substrate 90 which, in one actual embodiment of the invention, is 0.250 inch long, 0.040 inch wide, and 0.005 inch thick. This substrate can however range in thickness from 0.003 to 0.005 in., and it is formed from a material having low thermal conductivity. Steatite (a polycrystalline material containing magnesium oxide and silicon dioxide) is preferred because it has a thermal conductivity which is on the order of one magnitude less than conventional low thermal conductivity materials such as alumina. This is important because it significantly reduces the power required to heat the emitter to its operating temperature.
- Steatite a polycrystalline material containing magnesium oxide and silicon dioxide
- the substrate is preferably coated with a film of a dielectric material having low thermal conductivity such as a dielectric glass.
- Another substrate material that can be employed is fused silica.
- T-shaped electrical conductors or terminals 94 and 96 Bonded to the upper surface 92 of substrate 90 are two T-shaped electrical conductors or terminals 94 and 96.
- the head 98 of each conductor is 0.035 inch long; and the gap 100 between the conductors is 0.030 inch.
- Terminals 94 and 96 are preferably formed of a platinum and gold containing cermet obtained by printing an ink such as DuPont's 4956 on the surface 92 of substrate 90 and then firing the substrate.
- a thick film or layer 102 of an emissive, electrically resistive material is obtained by firing Electro-Science Labs ESL3812 Ink. This ink contains a major proportion of platinum and has an operating temperature in the range of 250-300 degrees centigrade.
- the illustrated, exemplary, emissive layer 102 is 0.070 inch long; and the two ends 104 and 106 of the emitter overlap 0.020 inch onto the conductor 94 and the conductor 96 of emitter 80.
- the total overlap constitutes 57 percent of the total area of emissive layer 102. This is within the preferred and operable range of 50 to 60 percent.
- Overlaps in the range just described tend to keep the current density at the interfaces between emissive layer 102 and conductors 94 and 96 from becoming too high and causing emitter 80 to fail by burnthrough or fatigue cracking of the emissive layer.
- T-shaped configuration of conductors 94 and 96 is also contributing to the resistance to failure from exposure to excessive current densities. This is at least potentially superior to the more conventional rectangular or straight sided conductors as far as resistance to emissive layer burnthrough is concerned.
- the emissive layer 102 and substrate 90 of emitter 80 are so constructed and related as to optimize the performance of the emitter as the emissive layer is periodically heated to produce the wanted emission of radiant energy.
- k thermal conductivity of the layer material
- R T .sbsb.I, R T .sbsb.II and R T .sbsb.III are the thermal resistances for layers I, II and III respectively;
- I T ⁇ Thermal Current ⁇ or heat flow
- V T 61 Thermal Voltage ⁇ or temperature
- T o ambient temperature of the back surface of the layer
- T(x) temperature as a function of location in the layer (O ⁇ X ⁇ L);
- P ave average electrical power applied to the thick film resistor
- g(t) general on-off pulsing function
- the thermal model also makes it clear that the various parameters of the emissive element, as well as those of the substrate, have to be balanced to obtain an emitter that will emit infrared energy of predictable varying intensity. This variation is controlled by the voltage across the source.
- the majority of the energy generated by the dissipation of the power through the resistor is conducted away from the resistor through that component and the substrate of the emitter in the form of thermal energy or heat.
- the rate at which this heat is conducted away from the emissive element or resistor is controlled by the physical parameters of the resistor, conductor, substrate and mounting assemblies.
- the emissivity of the resistor surface is important to the performance of the emitter. It does no good to modulate the heat of the resistor surface if that resistor surface is inefficient in radiating the concomitant infrared energy.
- the emissivity and resulting emission of infrared energy (heat) from the resistor is negligible in terms of the total heat flow of the system, but it is quite important in the functioning of the resistor assembly as an efficient infrared radiation emitter.
- the total assembly of emitter components must be considered when modeling the heat flow since the resistor and conductors, as well as the substrate material, are all within one order of magnitude for all parameters. Consequently, changes in the thicknesses, when all other parameters are held constant, will significantly affect the temperature excursions. These effects are seen both analytically and experimentally.
- the emissive element thickness for a given resistance must be tightly controlled to obtain satisfactory performance. This is because the thermal conductivity of the emissive layer is much higher than that of the substrate. Since the emissive layer thickness is only about one-fourth to one-fifth that of the substrate, small variations in the emissive element thickness have large effects on the thermal performance.
- One important item that can be determined from the model is the wave shape of the emitted infrared radiation for a defined set of physical parameters. This is important because of the time and other savings that can be realized by not having to build and evaluate large numbers of prototypes. That is, the performance of an emitter is tied directly to the wave shape of the emitted energy. Consequently, one can use the thermal model to evaluate different sets of selected parameters without actually building and testing emitters with those parameters.
- one gas analyzer system with an infrared radiation emitter of the character defined by the thermal model requires at least a 16 volt drive at 48 Hz with a 10% duty cycle to provide sufficient emitter output for the system to function to specification. If the substrate material of the emitter were to be changed from steatite to alumina, the voltage would have to be increased to over 21 volts to obtain comparable performance. However, at this higher voltage, the resistor material breaks down due to overheating. Thermal effects such as these can be modeled and materials chosen that will allow for as high a peak temperature with as much modulation of the temperature and as low a dissipated power as possible.
- lead frame 82 is stamped from a sheet of conductive metal such as tin plated copper.
- the lead frame has two, generally similar, arcuate segments 108 and 110 connected by integral tabs 112 and 114, a conductor or terminal 116 integral with and extending radially from segment 108, and a second conductor or terminal 118 which is integral with and extends radially from lead frame segment 110 in the opposite direction at a location halfway around the circumference of the lead frame from terminal 116.
- each of the two lead frame segments 108 and 110 has a generally arcuate configuration.
- U-shaped alignment slots 120 and 122 open onto the periphery of segment 108, and a third, U-shaped alignment slot 124 opens onto the periphery of segment 110.
- conductor receiving slots 126 and 128 are also opening onto the peripheries of lead frame segments 108 and 110, respectively.
- emitter supports 130 and 132 are also found in lead frame 82.
- Support 130 is integral with and extends radially inward from, lead frame segment 108.
- Emitter support 132 is axially aligned with support 130. It is integral with, and extends radially inward from, lead frame segment 108.
- Emitter support 130 has an emitter receiving recess 134 on what will hereinafter be referred to as the bottom side 136 of lead frame 82; and a second emitter receiving recess 138 is formed in emitter support 132, also on the bottom side 136 of lead frame 82.
- One end 140 of emitter 80 is seated in emitter support recess 134 and bonded in place as by the illustrated epoxy adhesive 142.
- the epoxy adhesive draws emitter 80 into the position illustrated in FIG. 5. This locates the midpoint 144 of emitter 102 on the centerline 145 of emitter unit 28. This is important in that it optimizes the ability of mirror assembly 86 to collimate and focus the energy emitted from the thick film or layer 102; and this results in an optical beam of optimum quality being projected from emitter unit 28.
- emitter 80 is not bonded to that support but is, instead, free to move back and forth in the slot as indicated by arrow 148 in FIGS. 5 and 6.
- the substrate grows or increases in length due to thermal expansion; but this growth is accommodated rather than being constrained.
- the stresses which would be imposed upon emitter 80 if both ends were fixed are avoided, eliminating the damage to emitter 80 or complete failure of that component which might result if mechanical stresses were imposed upon it.
- the two terminals 94 and 96 are respectively connected to conductive segments 108 and 110 of the lead frame 82. Electrical conductors or leads soldered at opposite ends to the emitter unit terminals 94 and 96 and lead frame segments 108 and 110 are employed for this purpose. They are illustrated in FIG. 5 and identified by reference characters 149 and 150.
- lead frame terminals 116 and 118 are bent at right angles to the conductor segments 108 and 110 of the lead frame, and the emitter or lead frame assembly is then installed in the base 88 of radiant energy emitting unit 28.
- This component is a monolithic member. The environment in which this component operates can reach an elevated temperature due to heating by the emissive layer 102 of emitter 80.
- the base is therefore fabricated of a polysulfone or comparable polymer which will remain structurally stable at the temperatures it reaches during the operation of emitter unit 28 and as leads 149 and 150 are soldered to base-supported lead frame segments 108 and 110.
- Base 88 has a cylindrical configuration; a platform 151; and integral, annular wall segments 152 . . . 158 which extend upwardly from platform 151 with base 88 in the orientation shown in FIG. 4. Extending inwardly from each of wall segments 152, 154, and 158 is a boss 160, 162, or 164 configured to complement a corresponding one of the three U-shaped slots 120, 122, and 124 in the segments 108 and 110 of lead frame 82. Diametrically opposed slots 166 and 168 are formed in, and extend from the top to the bottom of, base 88. These slots open onto the exterior of the base, are slightly wider than the terminals 116 and 118 of lead frame 82, and are slightly deeper than the lead frame terminals. Consequently, the terminals 116 and 118 may be fitted within slots 166 and 168 when emitter unit 28 is assembled.
- the assembly of emitter 80 and lead frame 82 is installed in base 88 by aligning it relative to the base as shown in FIG. 4 and then displacing the emitter/lead frame assembly downwardly in the direction indicated by arrow 170 until the segments 108 and 110 of the lead frame are seated on the upper surface 172 of base platform 151.
- the radial bosses 160 . . . 164 of base 88 guide lead frame 82 relative to base 88 as the lead frame/emitter assembly is installed, then and thereafter maintaining the wanted relationship between the assembly and base.
- the emitter/lead frame assembly is retained in place by an appropriate adhesive (not shown) between the lead frame segments and the upper surface 172 of the platform.
- the two lead frame tabs 112 and 114 are removed, leaving gaps 174 and 176 between the lead frame segments 108 and 110.
- current applied to terminal 116 flows seriatim through: lead frame segment 108, lead 149, emitter terminal 94, emissive layer 102, emitter terminal 96, lead 150, and lead frame segment 110 to lead frame terminal 118. This results in emissive layer 102 being heated and emitting the wanted energy in the infrared portion of the-electromagnetic spectrum.
- the provision of the breakaway tabs 112 and 114 just discussed is an important feature of the present invention from the viewpoint of assembling emitter unit 28.
- the assembly of emitter 80 and lead frame 82 is quite fragile as are the connections from leads 149 and 150 to emitter terminals 94 and 96 and lead frame segments 108 and 110.
- the assembly would be difficult to handle, install, and align if lead frame segments 108 and 110 were separate components.
- lead frame segments 108 and 110 integrated With lead frame segments 108 and 110 integrated, however, this ceases to be a problem because the lead frame acts as a supporting frame as well as an assembly jig. Handling and installation are very much simplified, especially as the removal of tabs 112 and 114 subsequent to the installation of the emitter/lead frame assembly is easily accomplished.
- an emitter/lead frame assembly with separate lead frame segments would require a special and relatively difficult to use fixture to install; and, even then, handling of this fragile assembly would pose a problem.
- the lead frame can be made to serve as an integral, assembly fixture for the emitter and lead frame.
- emitter unit tube or cap 84 is installed.
- This component shown in FIGS. 3 and 8-10, is an annular member fabricated from a polymer with a high degree of structural stability such as acrylonitrile-butadiene-styrene (ABS).
- Cap 84 is of the same diameter as base 88. It has a flat platform 178 from which a circular array of annular bosses 180 . . . 188 separated by gaps 190 . . . 197 depend.
- Cap 84 is installed by displacing it relative to base 88 in the direction indicated by arrow 198 in FIG. 3, once the cap has been oriented relative to the base as shown in that figure. As this movement continues, the annular wall segments 152 . . . 158 of base 88 ride up through the slots or gaps 190 . . . 197 in cap 84 until the platform 178 of the cap is seated on the upper ends of the annular walls segments.
- cap 84 is secured to base 88.
- cap 84 With cap 84 installed, the gaps 190 and 194 between depending, annular segments 152, 154, 158, and 160 are aligned with the external slots or recesses 126 and 128 in base 88. This accommodates the two terminals 116 and 118 of lead frame 82 in cap 84.
- the remaining step in putting together emitter unit 28 is to install mirror component or assembly 86 in base 88.
- the mirror assembly is a monolithic member with a circular cross section.
- the mirror assembly also typically fabricated from ABS, is dimensioned to fit within the circular central bore 200 of emitter base 88.
- a circular recess 202 is formed in mirror assembly 86, and that recess opens onto the bottom side 204 of the mirror assembly.
- a second, parabolic surface 206 is formed in the opposite, upper side 208 of the assembly. Parabolic surface 206 is first plated with a typically 2 mil thick coating of copper and then over-plated with gold, the thickness of the gold layer typically being in the range of 2 ⁇ in. This provides a parabolic mirror for collimating and focusing the infrared radiation from emitter 80.
- the upper part 210 of mirror assembly 86 is stepped inwardly, leaving a pair of longitudinally extending, diametrically opposed lugs 212 and 214.
- the upper part 210 of the mirror assembly is cut away, leaving diametrically opposed, longitudinally extending grooves 216 and 218 with locations 90° removed from lugs 212 and 214.
- Mirror assembly 86 is installed in base 88 with its axis of symmetry coinciding with emitter unit longitudinal centerline 145. This is accomplished by moving the mirror assembly relative to the base as indicated by arrow 220 in FIG. 3. As this displacement continues, the just-described lugs and grooves 212 . . . 218 interact with corresponding, integral, longitudinally extending lugs 222 (only one of which is shown) and grooves 224 in base 88 to guide the mirror assembly relative to the base. As in the case of cap 84, an appropriate but not illustrated adhesive can be employed to hold the mirror assembly in place.
- notch 226 in the upper end of mirror component 86. This separates emitter 80 from the upper side 208 of the mirror component 86, eliminating the possibility of damage to the emitter or to the mirror-providing plating on the parabolic surface 206 of the mirror component.
- That system includes an H-bridge driver 230 with the emitter 80 of infrared source unit 28 connected across its outputs and timing circuits collectively identified by reference character 232. Circuits 232 supply timing signals to driver 230. The timing signals are derived from a, crystal oscillator (not shown) and then counted down to provide the desired pulse rate and duty cycle. A current implementation uses a 7 MHz oscillator to provide a 85.45 Hz pulse rate and 7.1 percent duty cycle.
- the driver contains logic circuits and power MOSFETs arranged in the so-called "H” configuration. This provides the capability to turn on opposite legs of the "H” so that the infrared radiation emitter 80 is easily driven in opposite directions.
- the magnitude of the voltage applied to the source is controlled by changing the input voltages +Vp and -Vp .
- Bipolar pulsing whether provided by the circuitry shown in FIG. 11 or in some other manner, is preferred. Pulsing of this character eliminates the hysteresis, migration of emitter materials, and other adverse effects of continually pulsing the emitter with energy of the same polarity.
- the detector side of transducer 24 includes a detector unit 30 and a power supply 32 for supplying biasing voltage to the detector unit.
- Detector unit 30 includes a boxlike housing 234 mounted on a printed circuit board 236.
- a monolithic, heat conductive, isothermal detector support 238 is installed in housing 234. This component is preferably fabricated from aluminum because of the high heat conductivity which that element possesses.
- Isothermal support 238 has a generally L-shaped configuration with two normally related, integral legs 240 and 242 separated by a transition section 244.
- the isothermal support is installed in detector unit housing 234 with locating and retaining lugs 246, 248, and 250 in housing 234 engaged in cooperating recesses 252, 254, and 256. These are located in the leg 240, transition section 244, and leg 242 of isothermal support 238.
- Supported from and mounted in isothermal support 238 are: (a) data and reference detectors 258 and 260, (b) a beam splitter 262, and (c) the detector heaters 264 and 266 and thermistor-type current flow-limiting device 268 of a detector heater system 270.
- This system is employed to keep the two detectors at exactly the same, selected temperature, typically with a tolerance of not more than 0.01° C.
- Detectors 258 and 260 are preferably made from lead selenide because of the sensitivity which that material possesses to electromagnetic energy having wavelengths which are apt to be of interest. Detectors of an appropriate character are disclosed in detail in parent application Ser. No. 07/528,059.
- Detectors 258 and 260 are supported from heat conductive support 238 along with beam splitter 262.
- the beam splitter has a generally parallelepipedal configuration and is fabricated from a material such as silicon or sapphire which is essentially transparent to electromagnetic energy with wavelengths of interest.
- the exposed front surface 272 of the beam splitter is completely covered with a coating (not shown) capable of reflecting to data detector 258 that infrared radiation impinging on the beam splitter which has a wavelength shorter than a selected value.
- a coating (not shown) capable of reflecting to data detector 258 that infrared radiation impinging on the beam splitter which has a wavelength shorter than a selected value.
- Preferred is a proprietary coating supplied by Optical Coating Laboratories, Inc., Santa Rosa, Calif.
- beam splitter 262 will reflect to data detector 258 as indicated by arrow 274 in FIG. 2 energy having a wavelength shorter than about 4 microns.
- the energy of longer wavelengths is, instead, transmitted through the beam splitter to reference detector 260 as is suggested by arrow 276 in the same figure.
- Optical bandpass filters 278 and 280 are mounted in isothermal support 238 in front of data and reference detectors 258 and 260. Bandpass filters 278 and 280 are also obtained from Optical Coating Laboratories, Inc.
- the data detector bandpass filter 278 is centered on a wavelength of 4.260 ⁇ m and has a bandwidth of 0.10 ⁇ m. This is two times narrower than the band passed by filter 278.
- the carbon dioxide absorption curve is fairly narrow and strong, and bandpass filter 278 centers the transmission band within that absorption curve. Therefore, if there is a change in carbon dioxide level in the gas(es) being analyzed, the maximum modulation for a given change in carbon dioxide level is obtained. If the electromagnetic energy otherwise reached the data detector through the bandpass filter whether or not carbon dioxide was present in the gases being analyzed, the modulation of the carbon dioxide related output of data detector 258 would decrease; and accuracy would suffer.
- the reference detector optical bandpass filter 280 in detector unit 30 is centered on a wavelength of 3.681 ⁇ m and has a half power bandwidth of 0.190 ⁇ m. That filter transmits maximum energy near the band absorbed by data detector 258; but there are no interfering gases that would absorb energy in the transmitted bandwidth. Thus, nitrous oxide and water, the gases most apt to interfere, absorb on opposite sides of that bandwidth; and the selected region is almost certain to be one where there is no absorption. This absorption of maximum energy in an adjacent bandwidth is selected so that the output from reference detector 260 will be at least as large as the output from data detector 258. This contributes markedly to the accuracy of the gas concentration indicative signal subsequently obtained by ratioing the data and reference signals.
- the two signals to the data and reference detectors 258 and 260 are identical in time inasmuch as the detector-to-beam splitter distances are equal and the time required for the reflected and transmitted components of the beam to travel from beam splitter 262 to each of the two detectors 258 and 260 is, therefore, the same.
- the two detectors 258 and 260 spatially coincident in time from the optical viewpoint, the adverse effects on accuracy attributable to foreign material collecting on any of the optical windows 52, 54, 68, and 70 and a subsequently described window of detector unit 30 are also eliminated by the subsequent ratioing of the data and reference detector output signals.
- the infrared radiation reaches beam splitter 262 through an aperture 282 in the front wall 284 of detector unit housing 234.
- a typically sapphire window 286 spans aperture 282 and keeps foreign material from penetrating to the interior 288 of detector unit housing 234 before the detector unit 30 is installed in transducer housing 26 and if that housing is subsequently unsealed.
- light traps 290 and 292 are provided.
- the first of these is a triangularly sectioned, inwardly extending, projection of monolithic, isothermal support 238.
- the second, cooperating light trap 294 is aligned with, fixed in any convenient fashion to, and extends inwardly from that casing-associated ledge or lip 294 of support 238 which supports beam splitter 262.
- transducer 24 as thus far described is believed to be apparent from the drawing and the foregoing, detailed description of the invention.
- electromagnetic energy in the infrared portion of the spectrum is generated by heating the source or emitter 80 of emitter unit 28, preferably by applying bipolar pulses of electrical energy across the emitter unit as discussed above.
- the energy thus emitted is collated and focused into a beam by the mirrored parabolic surface 206.
- the thus formed beam of energy exits the emitter unit 28 through the central bore 200 in base 88 and a complementary central bore 296 in cap 84 and is propagated along optical path 50 across the gas(es) flowing through airway adapter 22.
- Energy in a species specific band is absorbed by the gas of interest flowing through the airway adapter (typically carbon dioxide) to an extent proportional to the concentration of that gas. Thereafter, the attenuated beam passes through the aperture 282 in the front wall 284 of the detector unit casing 234, is intercepted by beam splitter 262, and is either reflected toward data detector 258 or transmitted to reference detector 260.
- the optical bandpass filters 278 and 280 in front of those detectors limit the energy reaching them to specified (and different) bands.
- Each of the detectors 258 and 260 therefore outputs an electrical signal proportional in magnitude to the intensity of the energy striking that detector.
- signals are amplified by data detector and reference detector amplifiers (not shown) in detector unit 30 and then typically ratioed to generate a third signal accurately reflecting the concentration of the gas being monitored.
- the signal processor used for this purpose is independent of airway adapter 22 and transducer 24 and not part of the present invention. It will accordingly not be disclosed herein.
- the preferred lead selenide detectors 258 and 260 are extremely temperature sensitive; and it is therefore critical that these two detectors be maintained at the same temperature, preferably with the above-mentioned tolerance of not more than 0.01° C. Also, it was pointed out above that this desired degree of control is readily available from the detector heating system 270 made up of data detector heater 264, reference detector heater 266, and thermistor-type, temperature-limiting control 268.
- Heaters 264 and 266 in the illustrated detector unit 30 are precision, 25 ohm resistors with a tolerance of ⁇ 0.5 percent.
- Thermistor 268 is conventional.
- resistance heaters 264 and 266 are installed in circularly sectioned recesses 298 and 300 extending from side-to-side in the legs 240 and 242 of monolithic, isothermal support 238, producing efficient, conductive heat transfer between the heaters and the support.
- Thermistor 268 is installed in a similar, transversely extending, complementary aperture 302 in isothermal support transition section 244.
- the spatial relationship between heater 264 and data detector 258 and between heater 266 and reference detector 260 are identical, and the spatial relationship between thermistor 268 and each of the heaters 264 and 266 is also identical. Furthermore, the two heaters 264 and 266 are so located with respect to the associated detectors 258 and 260 that the thermal energy emitted from the heaters travels first across the detectors and then across the current flow-limiting thermistor 268 to heat dumps provided by gaps 304 and 306. These are respectively located between: (a) the leg 240 of isothermal support 238 and the top wall 308 of detector unit housing 234, and (b) the rear wall 310 of the housing and the leg 242 of the isothermal support. The heat flow paths are identified by arrows 312 and 314 in FIG. 2. As a consequence of the foregoing and the high thermal conductivity of isothermal support 238, the data and reference detectors 258 and 260 can readily be maintained at the same temperature.
- FIG. 19 A wiring diagram for detector heating system 270 is shown in FIG. 19. Turning then to that figure, the data detector heater 264 and reference detector heater 266 are supplied with +5 V power from a voltage regulator 316 incorporated in power supply 32. This voltage is modulated by the thermistor 268 of heating system 270 to control the output from the detector heaters and maintain isothermal support 238--and therefore data and reference detectors 258 and 260--at a constant, uniform temperature.
- Detector thermistor 268 is located in an external lead 318. That lead extends from voltage regulator 316 to a calibrator/connector 320 which may be located at some distance from transducer 24. Lead 322 and heater return 324 connect the external calibrator/connector 320 to the detector heaters 264 and 266.
- circuitry employed in power supply 32 for detector biasing and the modus operandi of that circuitry are in detail disclosed in parent application Ser. No. 528,059.
- transducer 24 also includes a data detector signal amplifier and a reference detector signal amplifier for increasing the levels of the signals outputted by data detector 258 and reference detector 260.
- transducers with detector units of the character disclosed herein are commonly used in environments in which electrical noise is prevalent. Electrostatic shielding is therefore preferably employed to isolate the data and reference detectors and associated circuitry from the adverse effects of EMI and other radiations in the ambient surroundings. This is yet another component of the transducer which is disclosed in parent application Ser. No. 528,509.
- Parent application Ser. No. 528,509 also discloses a novel casing for housing the electrostatic shielding and the detectors and other electrical and optical components of the transducer and for keeping foreign matter from reaching those components.
- Guide systems in the casing and in the electrostatic shield facilitate the assembly of the unit and the electrical connection of the electrostatic shield to the components shielded by that device.
- transducer 24 can be employed to advantage to measure the concentration of a designated gas flowing through the sampling passage 40 in airway adapter 22.
- moisture can condense out of the surrounding environment and collect on the optical windows 52 and 54 of the airway adapter and/or the windows 68, 70, and 286 of transducer 24. The result may be a degradation in performance and loss of accuracy.
- transducer housing 26 and the airway adapter 22 at an elevated temperature, preferably in the range of 42°-45° C. during the sampling process This is accomplished with a resistance-type heater 326.
- the casing heater is mounted in a recess 328 in the casing 26 of transducer 24.
- Resistance heater 326 keeps casing 26 and the airway adapter 22 assembled to transducer 24 at the desired temperature.
- casing heater 326 Operation of casing heater 326 is controlled by a thermistor 330 mounted on the heater and connected to calibrator/connector 320 by lead 332 (see FIG. 19).
- FIGS. 12-18 depict a second infrared radiation source or emitter unit 338 also constructed in accord with, and embodying, the principles of the present invention.
- emitter unit 338 The major components of emitter unit 338 are: (1) a base 340, (2) a lead frame 342, (3) an infrared radiation emitter or source 344, (4) conductive leads 346 and 348 for connecting emitter 344 across an appropriate power source, and (5) a mirror assembly 350 for collimating and projecting from unit 338 in the form of a beam infrared radiation outputted by emitter 344.
- Emitter 344 may be a duplicate of the emitter 80 discussed above.
- the base 340 of emitter unit 338 is a generally cylindrical component with a central aperture 352 through which the beam of infrared radiation formed and projected by mirror assembly 350 can escape to the exterior of unit 338.
- base 340 is preferably fabricated from a polysulfone or other polymer resistant to high temperatures.
- base 340 has a vertically oriented, circular side wall 354; an internal, horizontal ledge 356 surrounded by a side wall 354, and diametrically opposed locator lugs 358 and 360.
- the lead frame 342 employed in unit 338 is made up of two identical, arcuate segments 362 and 364. Like their counterparts in unit 28, they may be fabricated from tin plated copper. From the practical viewpoint, this employment of identical lead frame segments is important in that it reduces the number of parts that must be stocked. Lead frame segments 362 and 364 are also simpler and therefore considerably cheaper to fabricate than the more complicated, integrated lead frame 82 employed in emitter unit 28.
- Each of the lead frame segments 362 and 364 has an integral, inwardly extending, emitter support 366 with an emitter receiving groove 368.
- the groove opens onto the bottom sides 370 of the lead frame segments 362 and 364 and extends to the free ends 372 of emitter supports 366.
- each of the emitter supports 366 adjacent its emitter receiving recess or groove 368 is an elongated, radially extending slot 374.
- the locator lugs 358 and 360 of base 340 extend through the slots 374 in emitter supports 366. That locates lead frame segments 362 and 364 relative to base 340.
- lugs 376 and 378 are also employed to locate lead frame segments 362 and 364 in the base 340 of emitter unit 338. These are found at the ends of each lead frame segment's emitter support 366. With the lead frame segments assembled to emitter base 340 as shown in FIGS. 14-16, lugs 376 and 378 fit into complementary notches 380 and 382. These notches are located on opposite sides, and at the free ends 372, of the emitter supports. The sides of the notches thereby embrace the opposite sides of the supports 366 to hold in place the lead frame segments 362 and 364 in which those supports are incorporated.
- lead frame segments 362 and 364 are bonded in place and to emitter base 340 by an appropriate adhesive applied at the locations indicated by reference character 384 in FIG. 16. With the two lead frame segments 362 and 364 installed in emitter 344 in the manner just described, they are electrically isolated by the gaps 386 and 388 between the segments.
- emitter 344 is added to the assembly. It is seated in those emitter-receiving grooves 368 located in the lead frame segment-provided emitter supports 366 with the emissive layer 389 of the emitter centered on the longitudinal centerline 390 of unit 338 and spanning the gap 392 between the ends of emitter supports 366.
- End 394 of emitter 344 is bonded to its support 366. But, as in emitter unit 28, the opposite end 396 of the emitter is not. This leaves emitter 344 free to grow or expand longitudinally as it heats up during operation; and this keeps from there being imposed on the emitter stresses which might damage or destroy it.
- Emitter 344 is electrically connected to lead frame segments 362 and 364 after it is installed by electrical leads 398 and 400. At one end, lead 398 is soldered to lead frame segment 362. The other end of the lead is soldered to the terminal 94 at the fixed end 394 of the emitter. Lead 400 is similarly soldered at opposite ends to lead frame segment 364 and the terminal 96 at the opposite, floating end 396 of emitter 344.
- External leads 346 and 348 extend upwardly along the inside of base side wall 354 and into diametrically opposed, semicircular recess 402 and 404 in the rims of lead frame segments 362 and 364. Here, they are soldered to the commutator segments.
- mirror component 350 The final, and typically last to be installed, major component of emitter unit 338 is mirror component 350.
- This component shown in FIGS. 12, 13, 16, and 18, has a circular cross-section of the same diameter as base 340. It is typically fabricated from ABS polymer or a polymer with comparable characteristics.
- Grooves extending from end-to-end of mirror component 350 accommodate the external leads 346 and 348 of emitter unit 338. One of these grooves is shown in FIG. 16 and identified by reference character 406.
- the upper surface 408 of mirror component 350 has a parabolic configuration.
- Surface 408 is plated first with copper and then with gold to provide a mirror for collating the energy from emitter 344 and then focusing that infrared radiation into a beam projected from the emitter unit.
- a groove 410 extends around the periphery of mirror component 350.
- the lower end 414 of groove 410 also provides a seat for base 340. This keeps emitter 344 from engaging and perhaps being damaged by base 340.
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Abstract
Description
______________________________________ U.S. Pat. No. Patentee(s) Issue Date ______________________________________ 3,694,624 Buchta 26 Sep. 1972 3,875,413 Bridgham 01 Apr. 1975 4,378,489 Chabinsky et al. 29 Mar. 1983 4,620,104 Nordal et al. 28 Oct. 1986 4,914,720 Knodle et al. 03 Apr. 1990 ______________________________________
______________________________________ Emissive Element Density ρ Specific Heat C Thermal Conductivity k Thickness L Substrate Density ρ Specific Heat C Thermal Conductivity k Thickness L ______________________________________
Claims (38)
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/598,984 US5369277A (en) | 1990-05-23 | 1990-10-17 | Infrared source |
US07/599,888 US5251121A (en) | 1990-05-23 | 1990-10-18 | Power supplies |
CA002083509A CA2083509C (en) | 1990-05-23 | 1991-05-22 | Gas analyzers |
JP03510455A JP3118575B2 (en) | 1990-05-23 | 1991-05-22 | Gas analyzer |
PCT/US1991/003598 WO1991018279A1 (en) | 1990-05-23 | 1991-05-22 | Gas analyzers |
EP19910911005 EP0530309A4 (en) | 1990-05-23 | 1991-05-22 | Gas analyzers |
US08/300,383 US5616923A (en) | 1990-05-23 | 1994-09-02 | Gas analyzer cuvettes |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US52805990A | 1990-05-23 | 1990-05-23 | |
US07/598,984 US5369277A (en) | 1990-05-23 | 1990-10-17 | Infrared source |
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US52805990A Continuation-In-Part | 1990-05-23 | 1990-05-23 |
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US52805990A Continuation-In-Part | 1990-05-23 | 1990-05-23 | |
US08/300,383 Continuation-In-Part US5616923A (en) | 1990-05-23 | 1994-09-02 | Gas analyzer cuvettes |
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Publication Number | Publication Date |
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US5369277A true US5369277A (en) | 1994-11-29 |
Family
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Application Number | Title | Priority Date | Filing Date |
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US07/598,984 Expired - Lifetime US5369277A (en) | 1990-05-23 | 1990-10-17 | Infrared source |
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US5602398A (en) * | 1995-12-22 | 1997-02-11 | Pryon Corporation | Nondispersive infrared radiation source |
WO2000004351A2 (en) * | 1998-07-17 | 2000-01-27 | Kanstad Teknologi As | Infrared radiation source and its application for gas measurement |
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Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3306156A (en) * | 1957-02-19 | 1967-02-28 | Du Pont | Method and apparatus for photometric analysis |
US3694624A (en) * | 1969-07-16 | 1972-09-26 | Beckman Instruments Gmbh | Infrared radiator arrangement |
US3875413A (en) * | 1973-10-09 | 1975-04-01 | Hewlett Packard Co | Infrared radiation source |
US3916195A (en) * | 1974-06-17 | 1975-10-28 | Philco Ford Corp | Non-dispersive multiple gas analyzer |
US4378489A (en) * | 1981-05-18 | 1983-03-29 | Honeywell Inc. | Miniature thin film infrared calibration source |
US4620104A (en) * | 1982-02-22 | 1986-10-28 | Nordal Per Erik | Infrared radiation source arrangement |
US4859858A (en) * | 1986-12-04 | 1989-08-22 | Cascadia Technology Corporation | Gas analyzers |
US4859859A (en) * | 1986-12-04 | 1989-08-22 | Cascadia Technology Corporation | Gas analyzers |
US4914720A (en) * | 1986-12-04 | 1990-04-03 | Cascadia Technology Corporation | Gas analyzers |
-
1990
- 1990-10-17 US US07/598,984 patent/US5369277A/en not_active Expired - Lifetime
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3306156A (en) * | 1957-02-19 | 1967-02-28 | Du Pont | Method and apparatus for photometric analysis |
US3694624A (en) * | 1969-07-16 | 1972-09-26 | Beckman Instruments Gmbh | Infrared radiator arrangement |
US3875413A (en) * | 1973-10-09 | 1975-04-01 | Hewlett Packard Co | Infrared radiation source |
US3916195A (en) * | 1974-06-17 | 1975-10-28 | Philco Ford Corp | Non-dispersive multiple gas analyzer |
US4378489A (en) * | 1981-05-18 | 1983-03-29 | Honeywell Inc. | Miniature thin film infrared calibration source |
US4620104A (en) * | 1982-02-22 | 1986-10-28 | Nordal Per Erik | Infrared radiation source arrangement |
US4859858A (en) * | 1986-12-04 | 1989-08-22 | Cascadia Technology Corporation | Gas analyzers |
US4859859A (en) * | 1986-12-04 | 1989-08-22 | Cascadia Technology Corporation | Gas analyzers |
US4914720A (en) * | 1986-12-04 | 1990-04-03 | Cascadia Technology Corporation | Gas analyzers |
Non-Patent Citations (2)
Title |
---|
Solomon, "A Reliable, Accurate CO2 Analyzer for Medical Use", Hewlett-Packard Journal, Sep. 1981, pp. 3-11. |
Solomon, A Reliable, Accurate CO 2 Analyzer for Medical Use , Hewlett Packard Journal, Sep. 1981, pp. 3 11. * |
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